Thioglycerol-nitrogen base molecular complex

ABSTRACT

A thioglycerol-nitrogen base molecular complex useful as a depilatory; complexes are unimolecular or hemimolecular.

United States Patent 1191 Yablonsky 1451 Apr. 17,1973

[541 THIOGLYCEROL-NITROGEN BASE MOLECULAR COMPLEX [75] Inventor: HarveyA. Yablonsky, Elizabeth,

[73] Assignee: Bristol-Myers Company, New York,

[22] Filed: Dec. 15, 1971 [21 Appl. N0.E 208,441

' Related US. Application Data [62] Division of Ser. No. 812,903, April2, 1969, Pat. No.

[52] US. Cl ..260/309, 8/16 F, 260/284 R,

260/243.4 R, 260/309, 260/326.8, 260/551 R, 2 60/583 EE, 260/584 R 51Im. c1..... ..C07C 149/24, C07c 149/14 Primary Examiner-Lewis GottsAssistant ExaminerD. R. Phillips Attorney-Willian1 F. Ross, III et al.

[5 7] ABSTRACT A thioglycerol-nitrogen base molecular complex useful asa depilatory; complexes are unimolecular or hemimolecular. 1

8 Claims, No Drawings THIOGLYCEROL-NITROGEN BASE MOLECULAR COMPLEX Thisis a division of application Ser. No. 812,903, filed Apr. 2, 1969 nowU.S. Pat. No. 3,686,296.

Th 1s invention relates to depilatory compositions. More particularly,it concerns depilatory compositions wherein the active depilating agentis a molecular complex of thioglycerol and a nitrogen base.

A variety of organomercapto compounds have been suggested for use in theprior art as depilatories. these, however, leave much to be desired withregard to the speed with which they remove hair at pHs which which aretolerable to the skin, e.g., pH 8.5 to 10.5. Thus, for example BritishPat. No. 636,181 proposes, as depilatories, mercapto carboxylic acids inconjunctlon with enough free organic base to make the solution alkaline.This composition lacks much with respect to the rate at which the hairmay be safely removed from the skin.

British Pat. No. 693,438 concerns a depilatory composition whichcomprises a combination of thioglycerol with certain inorganic bases,such as the hydroxides of the alkali metal or the alkaline earth metals.Again, the inorganic base is merely added in sufficient quantity toestablish a certain alkaline pH. This too leaves much to be desiredregarding the rate at which the hair may be safely removed.

it has now been found that molecular complexes formed between nitro'genbases and thioglycerol in which the molar ratio of nitrogen base tothioglycerol or thioglycerol to nitrogen base is 1:1 or 1:05 are highlyefficient depilatory agents. These are particularly effective in aqueouscompositions which have a pH in the range of 8.5 to 10.5.

it is, accordingly, an object of the present invention to providedepilatory compositions which are highly efficient in rapidly removinghair from skin, said compositions being most effective in the pH rangeof about 8.5 to 10.5.

It is also an object of the present invention to provide depilatorycompositions of the type mentioned in the above object in which theactive depilatory agent is a molecular. complex of a nitrogen base andthioglycerol. Other and more detailed objects of this invention will beapparent from the following description and claims.

As noted above, the active depilatories of the present invention arenitrogen base-thioglycerol moecular complexes. These complexes may beexpressed generically by the formulas selected from the group consistingof:

[A], [HSCH CH HCH,OH]eb l and [A], [HSCH CH OHCH OH]ca u in which A is anitrogen base and the ratio a/b, i.e., the molar of nitrogen base tothioglycerol or thioglycerol to nitrogen base is l or 0.5.

The stoichiometry of these complexes vary with the nitrogen baseselected. It has been determined in a manner known in the piror art,through studies of the fluidities of aqueous solutions containing thematerials as a function of mole fractions of the nitrogen base. See thefollowing authorities:

Dunstan and Thole, VISCOSITY 0F LIQUIDS, Page 44.(London, 1917).

Faust, 0., ZEIT. PHYSIK. CHEM., 79 (97) 1912.

Hatschek, Emil, THE VISCOSITY OF LIQUIDS,

S., ZEIT.

examples of the latter. This stoichiometry is also reflected in theactivity of compositlons containing thioglycerol and employing varyingamounts of nitrogen base. it has been found that the presence of thenitrogen base generally enhances the depilatory activity of theparticular thio compound. However, nitrogen base concentration in excessof that necessary for complete complex formation does not increase thedepilation activity'above the completely complexed thio mixture. On theother hand, when the concentration of the nitrogen base is below thatnecessary for complete complexing of the thio compound, the depilationactivity is appreciably diminished.

A screening method has been developed for quantitatively evaluating thedepilatory activity of a composition. This is based on the observationthat human hair undergoes a characteristic form of swelling in manydepilating solutions. ,This swelling may be reduced to two sequentialevents: pp a. cross sectional swelling and b. longitudinal swelling.

Both of these swellings when plotted against time produce a sigmoidcurve. The sigmoid character is,

however, more clearly defined in the case of the longitudinal This has,Thihas, accordingly, been adopted for measurement of the depilatoryactivity. 7

The measurement T the time period at which the maximum rate oflongitudinal swelling is initiated, is taken as a quantitativeindication of the effectiveness of a depilating solution. A preparationpossessing a T value of 3 minutes is capable of completely depilatingarabbits belly in less than a minute. A number of wellknown commercialdepilatory preparations for human skin have T values in the range ofabout 25 minutes. It has been found that while the hair remains intact,the T value may for all intents and purposes be considered independentof the cuticle conditions.

The fact that the nitrogen bases of this invention do not merely serveto render the final composiions alkaline, is shown by the followingobservation:

Two aqueous solutions were prepared, one. utilizing completely complexthe compound employed, i.e., thioglycerol in the molar ratio of lMzlM.Hydrochloric acid was then added to the latter solution to increase itshydrogen ion concentration and bring it to the same level as the firstsolution. The depilating activity of a each of the solutions weredetermined as measured by the T value. The first solution had a value of6-7 whereas the second solution had a value of 1.5-2; showing anappreciably greater depilatory aciivity in solution two containing acomplex of the present invention.

Any of a large number of nitrogen bases and mixtures thereof may beemployed in preparing the complexes of this invention. However, the easeof complex formation increases with the increase of the K, of thenitrogen base. This is also correlated with the increase indepilatoryactivity of the product if the evaluation is carried out inthe desired pH range, i.e., 8.5 to 10.5. Generally, it may be statedthat nitrogen bases having a K, in the range of about l' to.10' arequite suitable for-the present purposes.

The nitrogen bases which have been found to be advantageous in thisinvention vary quite widely structurallyand include such lower alkylamine (one to six carbon atoms) AS methylamine, dimethylamine,ethylamine, isopropyl amine, di-isopropyl amine, di-npropyl amine,methyl isopropyl amine, dimethyl isopropyl amine, acetamidine,cyclohexyl methyl amine, isobutyl amine, tert. butyl amino cyclohexane;and such lower alkanol amines one to six carbon atoms) asmonoethanolamine, triethanolamines, 6 hydroxy-n hexylamine, 4 hydroxy-nbutylamine, 5 hydroxy-l-pentylamine; urea, heterocyclic nitrogen basessuch as imidazole', 1,2 dimethyl-2 pyrroline, piperidine, quinuclidine,pyrrolidine, 2 cyclohexyl pyrrolidine, pyrroline guanidine and guanidinehydrochloride, etc.

Another class of nitrogen bases that are especially useful for thepresent invention is sold under the trade designation DERIPHAT. Theseare described by the form ulas: v

RCH NHCH CH COOm ill and )2 [V wherein M is a slat-forming cation (e.g.,Na or H) and R is the hydrocarbon moiety of the long-chain fatty acidRCOOH, e.g., (C, to C and preferably C to C,,) fatty acid. These includesodium N-coco-B- aminopropionate (DERIPHAT 151); N-coco-Bamino propionicacid (DERIPHAT 151C); N-lauryl, myristyl- B-amino propionic acid(DERIPHAT 170C); disodium N-tallow-B-iminopropionate (DERIPHAT 154);disodium N-lauryl-B-iminopropionate (DERlPHAT 160) and the partialsodium salt of N-lauryl-B- iminopropionic acid. These are particularlysuitable because of the extremely low order of mercaptan odor exhibitedby complexes made from these bases, an odor which is a drawback in manycommercial products.

Still another class of nitrogen bases that is suitable for the presentpurposes is sold under the trade designation MlRANOL. These are definedby the general formula:

N CH2 CII2CII2ORI l| R-C-- -21 CIIzCOOM V in which:

a. R is the hydrocarbon moiety of the long-chain fatty acid RCOOH,(e.g., C to C,,, preferably C, to fatt acids);

b. R, is H, Na or CH,COOM;

c. M is Na, H or an organic base and (1. G is OH, an acid salt or thesalt of an anionic surface active sulfate or sulfonate.

These are described in US. Pat. No. 2,528,378, 2,773,068 and 2,781,354.Specific compounds of this character that can be employed in thisnnvention are set out in Tables II and Ill below.

TABLE II /C g2 IE1 (IE2 RC--NCH2CH20CHQCOOM:

H CHzCOOMz VI R RCOOH which serves M, M, Trade as source for RDesignation C,,H coconut oil acids Na Na MIRANOL C2M CONC C,,H coconutoil acids H H MlRANOL CZM-SF CONC caprylic and Na Na MIRANOL JEM CONC Aethylhexoic C-,H,, caprylic Na Na MIRANOL 12M CONC C,,H linoleic Na NaMIRANOL L2M-SF CONC TABLE III /Cll2 I? (I II! (7" -N*(ii|2(iii2i)l\1|()ll (lllzUUUMz Vll RCOOH which serves M, M I Trade as source for RDesignation c m, lauric Na Na MIRANOL HM CONC C,,H oleic H Na MlRANOLOM-SF CONC C,,H capric H Na MIRANOL SM CONC C,,H stearic H Na MIRANOL Afurther class of nitrogen bases that has been found to be useful inpreparing the complexes of the present invention is marketed under thetrade designation MONATERICS. These are substituted imidazolines offormula:

lI2(3-1DI llzC CR C llgCllz()-C1I2CII2-COOH wherein R is a long-chainhydrocarbon moiety (e.g., C -C and preferably C,-C, derived the fattyacid RCOOH. Particular compounds of this character that are employedherein are given in Table IV below:

TABLE IV R in Formula Origin of Moi Vlll R Weight Monateric C-A C-,-C,-,coconut fatty acids 360 Monateric L-A C,, lauric acid 340 Monateric O-AC, oleic acid 4 l 7 Monateric S-A C,,-C,, stearic acid 4 l 0 1n usingthe molecular complexes of the present invention as depilatories it ishighly desirable to incorporate them in an aqueous base. The amount ofwater contained in these aqueous composition can vary. In general, thewater will constitute between about 20 to 80 percent by weight of thetotal finished product.

The natural pH of the complexes formed between the nitrogen bases andthe thiogiycerol will vary depending upon the nitrogen base selected orthe relative amounts of the respective components of the complex.

The most effective pH range for depilating with the present complexes ispH 8.5 to 10.5. Where the natural pH is too low, it may be increased byusing any suitable base. Methylamine has been found to be especiallysuitable for this purpose although other bases, e.g., NaOH may also beemployed. Similarly, where the natural pH of the complex is too high,e.g., above 10.5, it may be brought into the proper range with an acid.Hydrochloric acid has been used to advantage for this purpose.

The amount of the thioglycerol-nitrogen base complex contained in acomposition relative to the total weight of the composition will varydepending on the particular nitrogen base selected and the resultsdesired. In general, however, it will constitute between 20 to 80percent by weight of the total composition.

which are mentioned below:

a. fast acting depilatory (wipe on, wipe off);

b. self-neutralizing permanent waving solution;

0. hair straightener (anti-kinking solution);

d. non-gum, non-grease mens hair groom;

e. shaving cream which will appreciably condition hair and facilitateshaving; I

f. menspre-shave lotion.

In using the compositions of the present invention as depilatories,procedures well known to those skilled in the art are employed. Thecompositions are. applied to areas of skin from which the hair is to beremoved. This is' allowed to remain in contact with the hair for no morethan about 4 minutes after which it is wiped off taking off the hair.

The following examples are further illustrative of the presentinvention. It is to be understood, however, that the invention is notlimited thereto.

EXAMPLE 1 An aqueous solution was prepared containing 1.0 M thioglyceroland 1.0 M methylamine. The pH of this composition was adjusted to withNaOH solution. This composition when applied to a hair penetrated thecuticle of the hair in one-half of a minute. It had a T value of 1.8 andwhen applied to the skin removed the hair in under 4 minutes.

The following Examples are given in tabular form. These are also aqueoussolutions comparable to that prepared in Example 1. The correspondingdata is givenfor each compositon TABLE 11V Ex. Concen. of Nitrogen pHand agent T No. Thiogly- Base and used to adjust cerol Concentration thepH 2 0.75 M imidazole 10.0 2.0

1.5 M (methylamine) 3 y 1.0 M imidazole 9.5 i 3.0

0.5 M (NaOH) 4 1.0 M imidazole 10.0 4.5-

- 0.5 methylamine) 5.0 5 1.0 M imidazole 9.0 5-6 2.0 M (methylamine) 62.0 M imidazole 8.75 6-7 4.0 7 1.0 methylamine 10.0 2-

2.0 M 2.5 imidazole 0.5 M 8 1.0 M ethylamine 10.0 4.0

1.0 M (NaOH) 9 1.0 M Na-N-coco- 9.5 3.75

aminopropionate (DERIPHAT 151C] 1.0 M 10 l 0 M N-coco-amino- 10.0 2.50

propionic acid (methyl- (DERIPHAT 151C) amine) 1.0 M 11 1.0 M DERIPHAT151C 10.0 3-4 0.5 (methylamine) 12 1.0 M DERIPHAT 151C 9.5 2-3 1.0 M(methylarnine) 13 1.0 M DERIPHAT 151C 10.0 4-

2.0 M (methylamine) 4.5 14 1.0 M MONATERlC 9.5 3.70

0.5 M 15 1.0 M MONATERIC LA 9.5 6-7 1.0 M (methylamine) 16 1.0 MMONATERIC LA 1 9.5 3-

2.0 M (methylamine) 3.5 17 1.0 M MIRANOL C2M 9.5 4-

SF (methylamine) 4.5 0.5 M 18 l 0 M MIRANOL C2M 10.0 3.5-

SF. (methylamine) 4.0 0.5 19 1.0 M MIRANOL C2M 9.5 6-7 SF (methylamine)1.0 M 20 2.0 M urea 10.0 4-5 4.0 M N(NaOH) 21 0.5 M urea 9.0 12- 1.0 M(NaOH) 14 22 1.0 M urea 10.0 45

2.0 M (NaOH) 23 0.5 M dimethylamine 11.5 45

1.0 M I 24 1.0 M dimethylamine 9.5 8-9 2.0 M (HCl) 25 2.0 Mdimethylamine 11.5 10- 4.0 M 12 26 0.5 M methylamine 11.5 5-6 1.0 M 271.0 M methylamine 10.0 1.5-

1.0 M 2 28 1.0 M methylamine 10.0 2.5-

2.0 M (HCl) 3.5 29 1.0 M methylamine 9.5 3.5-

2.0 M (HCl) 4.0 30 0.5 M monoethanolamine 10.0 6-7 1.0 M 31 1.0 Mmonoethanolamine 9.75 6-7.

1.0 M 32 1.0M monoethanolamine 10.0 t 4.5-

2.0 M 5' 33 2.0 M monoethanolamine 5-6 111 Example 1 through 33 above,water is used as the vehicle. However, in each case aqueous alcoholicsolutions may be used as the solvent for the complex. Methanol-watermixtures containing up to 50 percent by volume of methanol may be usedin place of the water. When ethanol is employed it may constitute up toabout 25 percent by volume of the aqueous alcoholic vehicle.

The following examples illustrate compositions of the present inventionemploying gels or cream bases as the vehicle for thethioglycerol-nitrogen base complex.

EXAMPLE 34 thioglycerol .OM Na-N-coco-B-aminopropionate .OM

lauryldimethylamine oxide 10% by wt.

This product has a natural pH of 9.5 and is in the form ofa gel. It hada T value of from about 2.0 2.5.

EXAMPLE 35 A cream base was prepared containing the followingingredients in percent weight:

Cream Base isopropyl palmitate 4.0 hexachlorophele 0.5 hexachlorophene3.0 merthiolate .005 water to l()% Using this base as a solvent, acomposition was prepared containing thioglycerol and MIRANOL C2M-SF (SeeTable II above) in concentrations of 1M respectively. The pH of thiscomposition was adjusted to 9.5 with NaOH. The composition had a T valueof 4.0 4.4.

EXAMPLE 36 Using the base described in EXAMPLE 35 as solvent, acomposition was prepared containing thioglycerol and methyl amine inconcentrations of 1M respectively. This material had a natural pH of anda T value ofabout 2.0 2.5.

EXAMPLE 37 derstood that many changes and modifications may be madewithout departing from the spirit of this invention.

What is claimed is:

l. A nitrogen base-thioglycerol molecular complex having a formulaselected by the group consisting of:

and

in which A is a nitrogen base and the molar ratio a/b is l or 0.5.

2. A complex according to claim 1 wherein the nitrogen base has a Kvalue in the range of from 10' to 10' I 3. A complex according to claim1 wherein the nitrogen base is a lower alkyl amine.

4. A complex according to claim 1 nitrogen base is a lower alkanolamine.

5. A complex according to claim 1 nitrogen base is imidazole.

6. A complex according to claim 1 nitrogen base is of the formula:

wherein the wherein the wherein the in which:

a. R is a hydrocarbon moiety of the long-chain fatty acid RCOOH; b. R isH, Na or --CH COOM; c. M is Na, H OR A salt-forming organic base; d. Gis OH, an acid salt or the salt of an anionic surface active sulfate orsulfonate. 7 A complex according to claim 1 wherein the nitrogen base isof the formula:

(JllzLllzO ()llzC H2000 ll.

in which R is the long-chain hydrocarbon moiety derived from the fattyacid RCOOH.

8. A complex according to claim 3 in which the lower alkyl amine ismethylamine.

2. A complex according to claim 1 wherein the nitrogen base has a Kbvalue in the range of from 10 10 to 10 1.6.
 3. A complex according toclaim 1 wherein the nitrogen base is a lower alkyl amine.
 4. A complexaccording to claim 1 wherein the nitrogen base is a lower alkanolamine.5. A complex according to claim 1 wherein the nitrogen base isimidazole.
 6. A complex according to claim 1 wherein the nitrogen baseis of the formula:
 8. A Complex according to claim 3 in which the loweralkyl amine is methylamine.